A mechanical hydraulic torque converter for horizontal wells

Abstract

This invention relates to a horizontal well mechanical hydraulic torque converter, belonging to the technical field of oil and gas drilling tools. The invention discloses a horizontal well mechanical hydraulic torque converter, comprising a drive shaft, an upper housing, a drive shaft positioning housing, a TC bearing assembly, a universal joint housing, a universal joint assembly, a stator housing, a hollow rotor, a middle housing, a torque separation assembly, a lower connector, and a manifold assembly. The universal joint assembly is installed inside the universal joint housing, and its two ends are respectively connected to the drive shaft and the hollow rotor. One end of the manifold assembly is connected to and communicates with the torque separation assembly, and the other end communicates with the outlet of the lower connector. The manifold assembly has a manifold hole communicating with the cavity. The upper housing, universal joint housing, stator housing, middle housing, and lower connector are connected sequentially. This invention's tool is driven by both the upper drill string speed and the drilling fluid flow rate. When the drilling fluid discharge rate is determined, the parameters can be adjusted according to the drill pressure-speed-output torque reference chart to ensure the tool's drag reduction performance and directional drilling efficiency.

Description

Technical Field

[0001] The invention relates to a horizontal well mechanical hydraulic torque converter, belonging to the technical field of oil and gas resource drilling tools. Background Art

[0002] The effective use of unconventional oil and gas is of critical strategic significance for alleviating the contradiction between oil and gas supply and demand, ensuring my country's energy security, promoting the low-carbon transformation of energy structure, and promoting carbon sequestration. Horizontal wells are an important means to achieve the scale and efficiency of unconventional oil and gas resources such as shale gas development, but horizontal well drilling generally faces problems such as high drill string friction, severe directional "support pressure", and low directional efficiency. At present, it has become one of the technical bottlenecks restricting the optimal and fast drilling of unconventional oil and gas horizontal wells. Mechanical drag reduction technology is an effective means to reduce horizontal well drilling friction and improve directional operation efficiency, but its drag reduction performance under different well conditions varies. Overall, the drag reduction effects of different drag reduction technologies are as follows: rotary steering drilling system > torsion pendulum drilling system > hydraulic oscillator. To this end, a hydraulic torque converter drilling tool based on differential pressure control is designed based on the operating advantages of rotary steering and low-cost bent screw, which can exploit oil and gas resources at low cost and high efficiency.

[0003] Compared with patent CN115467907, the currently disclosed domestic literature requires that when switching the working mode, the tool needs to be lifted a certain distance from the bottom of the well, and then a control command is sent to the tool to switch the working mode of the tool through the electrical components. The present invention adopts mechanical speed control to avoid the problem of electrical components failing in complex underground environments, and has a higher safety factor. At the same time, patent CN116291247 uses a spring piston as a switch assembly, and uses the drilling fluid pressure to drive the switch of the spring piston to achieve the switching of the working mode. The present invention adopts a nozzle hole type pressure difference controller to avoid the situation where the spring is corroded by the drilling fluid and rusts and fails, and has a longer service life. Summary of the invention

[0004] The purpose of the present invention is to provide a horizontal well mechanical hydraulic torque converter in view of the problems existing in the prior art.

[0005] The technical solution provided by the present invention to solve the above technical problems is: a horizontal well mechanical hydraulic torque converter, comprising a hollow drive shaft, an upper housing, a drive shaft positioning housing, a TC bearing assembly, a universal shaft housing, a universal shaft assembly, a stator housing with a screw stator, a hollow rotor, a middle housing, a torque separation assembly, a lower joint, and a confluence assembly;

[0006] The drive shaft is fixed in the upper housing through the drive shaft positioning housing and the TC bearing assembly; the universal shaft assembly is installed in the universal shaft housing, and the two ends are respectively connected to the drive shaft and the hollow rotor;

[0007] The cardan shaft assembly is provided with a flow guide hole and a flow guide cavity, the flow channel of the drive shaft is communicated with the flow guide cavity, and the flow guide cavity is communicated with the cardan shaft housing and the gap between the cardan shaft assembly through the flow guide hole;

[0008] The hollow rotor is installed in the stator housing, and one end is connected and communicated with the torque separation component installed in the middle housing, and the other end is provided with a drainage hole; the flow channel of the hollow rotor is communicated with the gap between the hollow rotor and the stator housing through the drainage hole;

[0009] The left end of the lower joint has an outlet, and the right end has a cavity connected to the outlet; the confluence component is installed in the cavity of the lower joint, one end of the confluence component is connected to and communicates with the torque separation component, and the other end is connected to the outlet of the lower joint, and the confluence hole connected to the cavity is provided on the confluence component;

[0010] The upper housing, the universal shaft housing, the stator housing, the middle housing and the lower joint are connected in sequence.

[0011] A further technical solution is that the TC bearing assembly includes a TC bearing moving ring, a lower retaining ring, an upper retaining ring, an upper sleeve, a TC bearing, a TC bearing stationary ring, and a bearing retaining ring. The TC bearing moving ring, the lower retaining ring, the upper retaining ring, the TC bearing, and the bearing retaining ring are sequentially sleeved on the drive shaft, the upper sleeve is sleeved on the lower retaining ring and the upper retaining ring, and the right ends of the upper retaining ring and the upper sleeve are both tightly against the left end face of the TC bearing; the drive shaft positioning shell is sleeved on the TC bearing moving ring and is threadedly connected in the upper outer shell, and the left end of the drive shaft positioning shell is tightly against the left end of the upper sleeve; the TC bearing stationary ring is sleeved on the bearing retaining ring, and its left end is tightly against the right end face of the TC bearing; the right end of the bearing retaining ring is tightly against the left end of the universal shaft assembly.

[0012] A further technical solution is that the cardan shaft assembly includes an upper portion of the cardan shaft, a middle portion of the cardan shaft, a lower portion of the cardan shaft and two cross shafts; the upper portion of the cardan shaft, the middle portion of the cardan shaft and the lower portion of the cardan shaft are all hinged with the cross shaft, and the lower portion of the cardan shaft is threadedly connected to the hollow rotor; the upper portion of the cardan shaft is provided with a channel and a guide hole connected to the drive shaft, and the channel is connected to the cavity between the cardan shaft housing and the cardan shaft assembly through the guide hole; the upper portion of the cardan shaft is threadedly connected to the drive shaft, and the lower portion of the cardan shaft is threadedly connected to the hollow rotor.

[0013] A further technical solution is that the merging assembly includes a merging joint, and the merging joint is radially provided with a plurality of merging holes.

[0014] A further technical solution is that the confluence component includes a first drilling fluid confluence pipe and a second drilling fluid confluence pipe which are connected to each other, the first drilling fluid confluence pipe and the second drilling fluid confluence pipe are installed in the cavity of the lower joint, the two ends of the first drilling fluid confluence pipe are respectively connected to the outlet and the second drilling fluid confluence pipe, one end of the second drilling fluid confluence pipe is connected to and communicates with the torque separation component, a pressure difference controller is provided on the second drilling fluid confluence pipe between the inner wall of the cavity of the lower joint and the outer wall of the second drilling fluid confluence pipe, and the second drilling fluid confluence pipe is provided with a confluence hole which is connected to the cavity of the lower joint.

[0015] A further technical solution is that the torque separation assembly includes a left pump rotor conversion joint, a left pump flexible shaft, a left end cover, a rotary seal housing, an inner liner, a left end cover, a right pump rotor conversion joint, a right pump flexible shaft, and a right end cover;

[0016] The left pump rotor conversion joint, the left pump flexible shaft, the liner, the right pump flexible shaft, and the right pump rotor conversion joint are all axially provided with flow passages and are connected in sequence;

[0017] The left pump flexible shaft and the right pump flexible shaft are respectively installed in the left and right ends of the liner, the liner is installed in the rotating seal shell, the left end cover and the right end cover are respectively sleeved on the left pump flexible shaft and the right pump flexible shaft, and installed on the left and right ends of the rotating seal shell; the left end of the left pump rotor conversion joint is connected to the hollow rotor, and the right end is connected to the left pump flexible shaft; the left end of the right pump rotor conversion joint is connected to the right pump flexible shaft, and the right end is connected to the confluence assembly.

[0018] A further technical solution is that pump rotor sealing rings are provided between the left pump rotor conversion joint and the hollow rotor, and between the confluence assembly and the right pump rotor conversion joint.

[0019] A further technical solution is that a conversion joint gasket is provided between the left pump rotor conversion joint and the left pump flexible shaft, and between the right pump rotor conversion joint and the right pump flexible shaft.

[0020] A further technical solution is that the left pump rotor conversion joint and the left pump flexible shaft, as well as the right pump rotor conversion joint and the right pump flexible shaft are connected by bolts.

[0021] A further technical solution is that a rotary sealing ring is provided between the rotary sealing shell and the left end cover and the right end cover.

[0022] The present invention has the following beneficial effects: the tool of the present invention is driven by the upper drill string rotation speed and the drilling fluid flow rate. When the drilling fluid displacement is determined, the parameters can be adjusted according to the drilling pressure-rotation speed-output torque reference chart to ensure the drag reduction performance and directional operation efficiency of the tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of the structure of an embodiment of the present invention;

[0024] Figure 2 It is a schematic diagram of the upper shell and the internal structure;

[0025] Figure 3 It is a schematic diagram of the universal shaft housing and internal structure;

[0026] Figure 4 Schematic diagram of stator housing and internal structure;

[0027] Figure 5 It is a schematic diagram of the middle shell and internal structure;

[0028] Figure 6 It is a schematic diagram of the lower joint and internal structure;

[0029] Figure 7 It is a structural schematic diagram of the pressure difference controller;

[0030] Figure 8 for Figure 7 Cross-section view in the AA direction;

[0031] Fig. 9 It is a structural schematic diagram of another embodiment of the present invention;

[0032] Fig.10 This is a schematic diagram of the structure of the junction.

[0033] As shown in the figure: 1-driving shaft; 2-TC bearing moving ring; 3-driving shaft positioning shell; 4-upper shell; 5-lower retaining ring; 6-upper retaining ring; 7-upper sleeve; 8-TC bearing; 9-TC bearing stationary ring; 10-bearing retaining ring; 11-universal shaft shell; 12-universal shaft upper part; 13-cross shaft; 14-universal shaft middle part; 15-universal shaft lower part; 16-hollow rotor; 17-stator shell; 18-screw stator; 19-pump rotor sealing ring; 20-left pump rotor conversion joint; 21-middle shell; 22-rotating sealing shell; 23-lining; 24-right pump flexible shaft; 25-rotating sealing ring; 26-right end cover; 27-confluence joint; 28-bolt; 31-second drilling fluid inlet pipe; 32-pressure differential controller; 33-lower joint; 34-first drilling fluid inlet pipe. DETAILED DESCRIPTION

[0034] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0036] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0038] A horizontal well mechanical hydraulic torque converter provided by the present invention comprises a hollow drive shaft 1, an upper housing 4, a drive shaft positioning housing 3, a TC bearing assembly, a universal shaft housing 11, a universal shaft assembly, a stator housing 17 with a screw stator 18, a hollow rotor 16, a middle housing 21, a torque separation assembly, a lower joint 33, and a confluence assembly;

[0039] The drive shaft 1 is fixed in the upper housing 4 through the drive shaft positioning housing 3 and the TC bearing assembly; the cardan shaft assembly is installed in the cardan shaft housing 11, and its two ends are respectively connected to the drive shaft 1 and the hollow rotor 16;

[0040] The cardan shaft assembly is provided with a flow guide hole and a flow guide cavity. The flow channel of the drive shaft 1 is communicated with the flow guide cavity. The flow guide cavity is communicated with the cardan shaft housing 11 and the gap between the cardan shaft assembly through the flow guide hole. The end of the flow guide cavity is closed. The purpose of such a setting is to ensure that the drilling fluid flows along the inner wall of the housing to the screw composed of the hollow rotor and the screw stator after flowing through the flow guide joint.

[0041] The hollow rotor 16 is installed in the stator housing 17, and one end is connected and communicated with the torque separation component installed in the middle housing 21, and the other end is provided with a plurality of radially distributed drainage holes;

[0042] The lower joint 33 has an outlet at its left end and a cavity connected to the outlet at its right end; the confluence assembly is installed in the cavity of the lower joint 33, one end of the confluence assembly is connected to and communicates with the torque separation assembly, and the other end is connected to the outlet of the lower joint 33, and a confluence hole connected to the cavity is provided on the confluence assembly;

[0043] The upper housing 4, the cardan shaft housing 11, the stator housing 17, the middle housing 21 and the lower joint 33 are connected in sequence.

[0044] The horizontal well mechanical hydraulic torque converter in the above-mentioned embodiment is mainly composed of a power part, a coupling part, and a pressure difference control part.

[0045] The power part is mainly composed of a drive shaft 1, a drive shaft positioning assembly, a TC bearing assembly, and an upper housing 4.

[0046] The lower part of the drive shaft is connected to the cardan shaft assembly through threads, and a plurality of radially distributed guide holes are opened on it. When the drive shaft 1 rotates, the torque can be transmitted to the cardan shaft assembly. At the same time, the drilling fluid flowing through the flow channel of the drive shaft 1 flows into the cavity between the cardan shaft assembly and the cardan shaft housing 11 through the guide holes under the action of centrifugal force;

[0047] The coupling part is mainly composed of a cardan shaft housing 11, a cardan shaft assembly, a hollow rotor 16, a stator housing 17, and a torque separation assembly.

[0048] The structure of the drive shaft 1 is similar to a hollow three-stage drive shaft, and its shaft is divided into a primary rod, a secondary rod, and a tertiary rod according to the size of the outer diameter. The top of the primary rod is connected to the upper drill string through a threaded connection to ensure the power input of the tool; the end of the secondary rod is formed with an arc-shaped groove for matching with the drive shaft positioning shell 3 to ensure that the drive shaft 1 will not move axially relative to other components in the tool; the middle part of the tertiary rod is interference-fitted with the TC bearing assembly housing to ensure the transmission of drilling pressure, and the drive shaft 1 can rotate relative to the upper housing 4; the end of the tertiary rod is connected to the universal shaft assembly through a threaded connection, so that the drive shaft 1 can transmit torque to the universal shaft assembly;

[0049] The universal shaft assembly is connected to the hollow rotor 16 by threads, and the hollow rotor 16 is provided with a plurality of radially distributed drainage holes, the purpose of which is to ensure that a portion of the drilling fluid flows into the screw motor cavity between the stator housing 17 and the hollow rotor 16, and the other portion is guided into the flow channel of the hollow rotor 16. The end of the hollow rotor is connected to the conversion joint in the torque separation assembly by threads.

[0050] The pressure difference control part is mainly composed of a confluence assembly and a lower joint 33; the confluence assembly is provided with a confluence hole to facilitate the confluence of the drilling fluid into the lower drilling tool;

[0051] The specific workflow is:

[0052] The drilling fluid flows in from the internal flow channel of the drive shaft 1, and all flows into the annular cavity between the cardan shaft assembly and the cardan shaft housing 11 through the diversion hole. When the drilling fluid flows through the diversion hole on the upper part of the hollow rotor 16, a part of the drilling fluid flows into the internal flow channel of the hollow rotor 16 through the diversion hole, and the rest of the drilling fluid flows into the screw gap cavity formed by the hollow rotor 16 and the screw stator 18. The liquid flowing into the screw gap cavity is determined by the rotation speed of the hollow rotor 16. The faster the rotation speed of the hollow rotor 16, the more drilling fluid flows into the screw gap cavity. Finally, the drilling fluid flowing into the screw gap cavity and the drilling fluid in the internal flow channel of the hollow rotor are reunited at the confluence assembly and flow to the lower drill string.

[0053] When the upper drill string drives the hollow rotor 16 to rotate through the drive shaft 1, part of the drilling fluid is sucked into the screw gap cavity, and the other part flows into the internal flow channel of the hollow rotor through the drainage hole. Under the condition of ignoring the pressure loss of the drilling fluid along the way, the drilling fluid pressure inside the hollow rotor flow channel is approximately equal to the drilling fluid pressure at the outlet of the gap cavity. Due to the effect of the drainage hole, the pressure of the drilling fluid at the entrance of the gap cavity is greater than the drilling fluid pressure in the internal flow channel of the hollow rotor, thereby generating a fluid pressure difference at both ends of the screw stator 18. Due to the shape of the inner wall of the screw stator, under the action of the drilling fluid pressure difference, the screw stator 18 will output a torque to the shell, and the torque value is jointly determined by the pressure difference at both ends of the gap cavity and the shape of the screw. During the working process of the tool, the working factors that affect the pressure difference at both ends of the gap cavity are mainly the upper drill string rotation speed and the drilling fluid displacement. The output torque of the tool can be adjusted by adjusting the rotation speed of the upper drill string and the drilling fluid displacement.

[0054] When guided drilling operations are required, in order to ensure a stable tool face, the lower drill string needs to maintain a sliding drilling state. The output torque of the tool can be controlled by adjusting the drilling fluid displacement and rotation speed. When the output torque value of the tool fluctuates above and below the drill bit counter-torque value, the lower drill string can be kept in a sliding drilling state. The floating range of its output torque depends on the friction torque range of the lower drill string.

[0055] When drilling in a vertical well section, the lower drill string needs to be rotated to further reduce the friction of the drill string. By adjusting the upper drill string speed and the drilling fluid displacement, the output torque of the tool is greater than the total torque of the drill bit reaction torque and the lower drill string friction torque, and the lower drill string can be rotated.

[0056] like Figure 2As shown, in this embodiment, a specific implementation of the TC bearing assembly includes a TC bearing moving ring 2, a lower retaining ring 5, an upper retaining ring 6, an upper sleeve 7, a TC bearing 8, a TC bearing stationary ring 9, and a bearing retaining ring 10. The TC bearing moving ring 2, the lower retaining ring 5, the upper retaining ring 6, the TC bearing 8, and the bearing retaining ring 10 are sequentially sleeved on the drive shaft 1, the upper sleeve 7 is sleeved on the lower retaining ring 5 and the upper retaining ring 6, and the right ends of the upper retaining ring 6 and the upper sleeve 7 are both tightly against the left end face of the TC bearing 8; the drive shaft positioning shell 3 is sleeved on the TC bearing moving ring 2 and is threadedly connected in the upper outer shell 4, and the left end of the drive shaft positioning shell 3 is tightly against the left end of the upper sleeve 7; the TC bearing stationary ring 9 is sleeved on the bearing retaining ring 10, and its left end is tightly against the right end face of the TC bearing 8; the right end of the bearing retaining ring 10 is tightly against the left end of the universal joint shaft assembly.

[0057] like Figure 3 As shown, in this embodiment, a specific implementation of the cardan shaft assembly is to include a cardan shaft upper portion 12, a cardan shaft middle portion 14, a cardan shaft lower portion 15 and two cross shafts 13; the cardan shaft upper portion 12, the cardan shaft middle portion 14 and the cardan shaft lower portion 15 are all hinged with the cross shaft 13, and the cardan shaft lower portion 15 is threadedly connected to the hollow rotor 16; the cardan shaft upper portion 12 is provided with a channel and a guide hole connected to the drive shaft 1, and the channel is connected to the cardan shaft housing 11 and the cavity between the cardan shaft assembly through the guide hole; the cardan shaft upper portion 12 is threadedly connected to the drive shaft 1, and the cardan shaft lower portion 15 is threadedly connected to the hollow rotor 16.

[0058] like Figure 5 As shown, in this embodiment, a specific implementation of the torque separation assembly is to include a left pump rotor conversion joint 20, a left pump flexible shaft, a left end cover, a rotary seal housing 22, an inner liner 23, a left end cover, a right pump rotor conversion joint, a right pump flexible shaft 24, and a right end cover 26; the inner liner 23 is a rubber inner liner;

[0059] The left pump rotor conversion joint 20, the left pump flexible shaft, the liner 23, the right pump flexible shaft 24, and the right pump rotor conversion joint are all axially provided with flow passages and are connected in sequence;

[0060] The left pump flexible shaft and the right pump flexible shaft 24 are respectively installed in the left and right ends of the liner 23, and the liner 23 is installed in the rotating seal shell 22. The left end cover and the right end cover 26 are respectively sleeved on the left pump flexible shaft and the right pump flexible shaft 24, and installed on the left and right ends of the rotating seal shell 22; the left end of the left pump rotor conversion joint 20 is connected to the hollow rotor 16, and the right end is connected to the left pump flexible shaft; the left end of the right pump rotor conversion joint is connected to the right pump flexible shaft 24, and the right end is connected to the confluence component.

[0061] In the embodiment of the torque separation component, in order to improve the sealing effect, the preferred implementation mode is that a pump rotor sealing ring 19 is provided between the left pump rotor conversion joint 20 and the hollow rotor 16, and between the confluence assembly and the right pump rotor conversion joint, a conversion joint gasket is provided between the left pump rotor conversion joint 20 and the left pump flexible shaft, and between the right pump rotor conversion joint and the right pump flexible shaft 24, and a rotating sealing ring 25 is provided between the rotating sealing housing 22 and the left end cover and the right end cover 26.

[0062] like Figure 5 As shown, in the embodiment of the torque separation assembly, the left pump rotor conversion joint 20 and the left pump flexible shaft, and the right pump rotor conversion joint and the right pump flexible shaft 24 are both connected by bolts 28 .

[0063] like Figure 1 and Figure 6 As shown, in another specific embodiment of the confluence assembly in this embodiment, the confluence assembly includes a first drilling fluid confluence pipe 34 and a second drilling fluid confluence pipe 31 which are connected to each other; the first drilling fluid confluence pipe 34 and the second drilling fluid confluence pipe 31 are installed in the cavity of the lower joint 33, the two ends of the first drilling fluid confluence pipe 34 are respectively connected with the outlet and the second drilling fluid confluence pipe 31, one end of the second drilling fluid confluence pipe 31 is connected and communicated with the torque separation assembly, a pressure difference controller 32 which is sleeved on the second drilling fluid confluence pipe 31 is provided between the inner wall of the cavity and the outer wall of the second drilling fluid confluence pipe, and the second drilling fluid confluence pipe 34 is provided with a confluence hole which is connected with the cavity;

[0064] Due to the design requirements of the pressure difference controller 32, the outer diameter of the end of the second drilling fluid inlet pipe 31 is reduced, and the second drilling fluid inlet pipe 31 is connected to the first drilling fluid inlet pipe 34 by threads. This method can increase or decrease the number of pressure difference controllers 32 by changing the end length of the second drilling fluid inlet pipe 31, thereby adjusting the drilling fluid pressure difference and output torque at both ends. At the same time, changing the number of pressure difference controllers 32 can also change the critical speed of the drive shaft when the output torque and the counter torque are balanced. The fluid flow area between the second drilling fluid inlet pipe 31 and the lower joint 33 is reduced, and the drilling fluid flow rate is increased, so that the drilling fluid is faster to enter the lower drilling tool.

[0065] In this way, the drilling fluid flowing into the screw gap cavity passes through the torque separation component and the differential pressure controller 32. The flow area of ​​the differential pressure controller changes, so that when the drilling fluid flows through the differential pressure controller, a certain pressure difference will be generated, and the drilling fluid pressure before the differential pressure controller is greater than the drilling fluid pressure after the differential pressure controller. The size of the second drilling fluid inlet pipe 31 can be changed to increase multiple differential pressure controllers 32, so that the drilling fluid produces different pressure differences.

[0066] Due to the action of the differential pressure controller, the drilling fluid pressure flowing into the screw gap cavity is greater than the drilling fluid pressure of the central pipe. The screw stator 18 adopts an equidistant line type of a common inner cycloid. Under the action of the drilling fluid pressure difference, the screw stator 18 will output a torque to the stator housing 17, and this torque is balanced with the counter torque of the lower drilling tool. The torque is related to the drive shaft speed and the number of differential pressure controllers 32. The faster the speed of the drive shaft 1, the greater the drilling fluid flow rate flowing into the screw gap cavity, the higher the drilling fluid pressure difference at both ends, that is, the greater the stator output torque. The output torque of the torque converter can be adjusted by adjusting the speed of the drive shaft 1.

[0067] When in the "directional drilling" mode, adjust the speed of the drive shaft 1 to balance the output torque with the counter-torque of the lower drill bit, that is, the upper drill string rotates, the lower drill string keeps sliding drilling, and the tool housing does not rotate. At this time, the torque converter is in the "off" state.

[0068] When in the "compound drilling" mode, the speed of the drive shaft 1 is increased so that the output torque is greater than the sum of the reaction torque and the friction torque of the lower drilling tool, that is, the drill string of the entire well is in a rotating state, and the tool housing also rotates in the forward direction. At this time, the torque converter is in the "closed" state.

[0069] like Fig. 9 and Fig.10 As shown, in this embodiment, a specific embodiment of the confluence component is a confluence joint; the confluence joint is radially provided with a plurality of confluence holes; the drilling fluid flowing into the screw gap cavity and the drilling fluid in the internal flow channel of the hollow rotor are reunited at the confluence joint and flow to the lower drill string.

[0070] The above description is not intended to limit the present invention in any form. Although the present invention has been disclosed through the above embodiments, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A horizontal well mechanical hydraulic torque converter, characterized in that: It includes a hollow drive shaft, an upper housing, a drive shaft positioning housing, a TC bearing assembly, a universal shaft housing, a universal shaft assembly, a stator housing with a screw stator, a hollow rotor, a middle housing, a torque separation assembly, a lower joint, and a confluence assembly; The drive shaft is fixed in the upper housing through the drive shaft positioning housing and the TC bearing assembly; the universal shaft assembly is installed in the universal shaft housing, and the two ends are respectively connected to the drive shaft and the hollow rotor; The cardan shaft assembly is provided with a flow guide hole and a flow guide cavity, the flow channel of the drive shaft is communicated with the flow guide cavity, and the flow guide cavity is communicated with the cardan shaft housing and the gap between the cardan shaft assembly through the flow guide hole; The hollow rotor is installed in the stator housing, and one end is connected and communicated with the torque separation component installed in the middle housing, and the other end is provided with a drainage hole; the flow channel of the hollow rotor is communicated with the gap between the hollow rotor and the stator housing through the drainage hole; The left end of the lower joint has an outlet, and the right end has a cavity connected to the outlet; the confluence component is installed in the cavity of the lower joint, one end of the confluence component is connected to and communicates with the torque separation component, and the other end is connected to the outlet of the lower joint, and the confluence hole connected to the cavity is provided on the confluence component; The upper housing, the cardan shaft housing, the stator housing, the middle housing and the lower joint are connected in sequence; The torque separation assembly includes a left pump rotor conversion joint, a left pump flexible shaft, a left end cover, a rotary seal housing, an inner liner, a right pump rotor conversion joint, a right pump flexible shaft, and a right end cover; The left pump rotor conversion joint, the left pump flexible shaft, the liner, the right pump flexible shaft, and the right pump rotor conversion joint are all axially provided with flow passages and are connected in sequence; The left pump flexible shaft and the right pump flexible shaft are respectively installed in the left and right ends of the liner, the liner is installed in the rotating seal shell, the left end cover and the right end cover are respectively sleeved on the left pump flexible shaft and the right pump flexible shaft, and installed on the left and right ends of the rotating seal shell; the left end of the left pump rotor conversion joint is connected to the hollow rotor, and the right end is connected to the left pump flexible shaft; the left end of the right pump rotor conversion joint is connected to the right pump flexible shaft, and the right end is connected to the confluence assembly.

2. A horizontal well mechanical hydraulic torque converter according to claim 1, characterized in that: The TC bearing assembly includes a TC bearing moving ring, a lower retaining ring, an upper retaining ring, an upper sleeve, a TC bearing, a TC bearing stationary ring, and a bearing retaining ring. The TC bearing moving ring, the lower retaining ring, the upper retaining ring, the TC bearing, and the bearing retaining ring are sequentially sleeved on the drive shaft, the upper sleeve is sleeved on the lower retaining ring and the upper retaining ring, and the right ends of the upper retaining ring and the upper sleeve are both tightly against the left end face of the TC bearing; the drive shaft positioning shell is sleeved on the TC bearing moving ring and is threadedly connected in the upper outer shell, and the left end of the drive shaft positioning shell is tightly against the left end of the upper sleeve; the TC bearing stationary ring is sleeved on the bearing retaining ring, and its left end is tightly against the right end face of the TC bearing; the right end of the bearing retaining ring is tightly against the left end of the universal shaft assembly.

3. A horizontal well mechanical hydraulic torque converter according to claim 2, characterized in that: The cardan shaft assembly includes an upper portion of the cardan shaft, a middle portion of the cardan shaft, a lower portion of the cardan shaft and two cross shafts; the upper portion of the cardan shaft, the middle portion of the cardan shaft and the lower portion of the cardan shaft are all hinged with the cross shaft, and the lower portion of the cardan shaft is threadedly connected to the hollow rotor; the upper portion of the cardan shaft is provided with a channel and a guide hole connected to the drive shaft, and the channel is connected to the cavity between the cardan shaft housing and the cardan shaft assembly through the guide hole; the upper portion of the cardan shaft is threadedly connected to the drive shaft, and the lower portion of the cardan shaft is threadedly connected to the hollow rotor.

4. The horizontal well mechanical hydraulic torque converter according to claim 1, characterized in that: The merging assembly comprises a merging joint, and the merging joint is radially provided with a plurality of merging holes.

5. The horizontal well mechanical hydraulic torque converter according to claim 1, characterized in that: The confluence assembly includes a first drilling fluid confluence pipe and a second drilling fluid confluence pipe which are connected to each other. The first drilling fluid confluence pipe and the second drilling fluid confluence pipe are installed in the cavity of the lower joint. The two ends of the first drilling fluid confluence pipe are respectively connected to the outlet and the second drilling fluid confluence pipe. One end of the second drilling fluid confluence pipe is connected to and communicates with the torque separation assembly. A pressure difference controller which is sleeved on the second drilling fluid confluence pipe is provided between the inner wall of the cavity of the lower joint and the outer wall of the second drilling fluid confluence pipe. The second drilling fluid confluence pipe is provided with a confluence hole which is connected to the cavity of the lower joint.

6. The horizontal well mechanical hydraulic torque converter according to claim 1, characterized in that: Pump rotor sealing rings are provided between the left pump rotor conversion joint and the hollow rotor, and between the confluence assembly and the right pump rotor conversion joint.

7. The horizontal well mechanical hydraulic torque converter according to claim 1, characterized in that: A conversion joint gasket is provided between the left pump rotor conversion joint and the left pump flexible shaft, and between the right pump rotor conversion joint and the right pump flexible shaft.

8. The horizontal well mechanical hydraulic torque converter according to claim 1, characterized in that: The left pump rotor conversion joint and the left pump flexible shaft, as well as the right pump rotor conversion joint and the right pump flexible shaft are both connected by bolts.

9. The horizontal well mechanical hydraulic torque converter according to claim 1, characterized in that: A rotary sealing ring is arranged between the rotary sealing shell and the left end cover and the right end cover.

Images